This invention relates to lateral end uprights for the feeding roll pair in chocolate refining machines.
As is known, in chocolate refining machines, chocolate paste is fed into the machine by means of a pair of feeding rolls. The feeding chamber is formed by the juxtaposed upper portions of said feeding rolls, and at the sides, by lateral end uprights or legs having a substantially wedge-like configuration wherein the sloping sides are replaced by arcuate portions bearing on said juxtaposed feeding rolls. More specifically, the uprights are made to bear on the rolls and an end stepped-down portion of said rolls, so that the sealing surface area is increased while forming an abutment shoulder on the roll against which springs or pneumatic device can be urged by means of wedges to improve the upright sealing. In the radial direction, said uprights bear on the rolls by gravity. Thus, a seal is achieved both against the radial and axial pressures.
In fixed axle roll refining machines, prior lateral end uprights can only provide a proper seal with the feeding rolls held truly in parallel and having exactly the same working lengths. In the instance of some slight differences in length, in fact, the uprights would only bear axially in the abutment step of the longer roll, to leave at the shortest roll a gap whereat product leakage occurs. Such leakage paths would also be formed in the event that the axes of the feeding rolls are not truly parallel to each other.
In recent years, chocolate refining machines have been disclosed (refer to Italian Patent Application No. 21 357/83 by the same Applicant) wherein the refining rolls are mounted oscillably in a horizontal plane to achieve an equivalent effect of crown variation in the refining rolls in order to affect the plasticity or viscosity of chocolate being refined. In such refining machines, the input roll of the feeding roll pair is also mounted oscillably in the horizontal plane, thereby in operation, the axle of the input roll is allowed to set obliquely in the horizontal plane relatively to the adjacent feeding roll in the pair, and consequently, with prior lateral end uprights, the above-mentioned chocolate leaking gaps would be formed even for small inclination angles on the order of 1 or 2 degrees.